<!DOCTYPE html>
<html lang="en">
  <head>
    <meta charset="UTF-8" />
    <meta name="viewport" content="width=device-width, initial-scale=1.0" />
    <title>Document</title>
  </head>
  <body>
    <form name="form">
      <p>
        <input type="text" name="username" value="hello" />
      </p>
      <p>
        <textarea name="desc"></textarea>
      </p>
    </form>
    <script>
      console.log(document.form.username);
      console.log(document.form.username.value);
      console.log(document.form.desc.value);

      setTimeout(() => {
        document.form.username.value = "hello jack";
        document.form.desc.value = "hello jack";
      }, 3000);
    </script>
  </body>
</html>
